Distance Nut to First Fret?

Most basses I've tested, are hard to intonate
If I intonate open E string and E string 12 fret
right, the F tone(first fret E string) will be to high.
I've heard it's because the nut is to close to first fret ( got an 5 string 34" with Daddario 040-125 )
Does anyone know the right distace?
( now it's 48.6mm from nut to top of fret)

It's probably caused by your nut being too high, not too far away from the fret... I read an article on BP online before they changed their website. It featured a setup masterclass with Anthony Jackson, where he adressed this problem. If I remember correctly, the solution was either to file your nut down, or something about bending your string behind the nut, don't ask my why that would help, but that's how i remember it. It's normal to have a sharp F.